CLINIMEX Aerobic Fitness Questionnaire: Proposal and Validation

Abstract Background: Cardiorespiratory (aerobic) fitness is strongly and directly related to major health outcomes, including all-cause mortality. Maximum oxygen uptake (VO2max), directly measured by maximal cardiopulmonary exercise test (CPET), represents the subject’s aerobic fitness. However, as CPET is not always available, aerobic fitness estimation tools are necessary. Objectives: a) to propose the CLINIMEX Aerobic Fitness Questionnaire (C-AFQ); b) to validate C-AFQ against measured VO2max; and c) to analyze the influence of some potentially relevant variables on the error of estimate. Methods: We prospectively studied 1,000 healthy and unhealthy subjects (68.6% men) aged from 14 to 96 years that underwent a CPET. The two-step C-AFQ describes physical activities with corresponding values in metabolic equivalents (METs) - ranging from 0.9 to 21 METs. Results: Application of C-AFQ took less than two minutes. Linear regression analysis indicated a very strong association between estimated (C-AFQ) and measured (CPET) maximal METs - r2 = 0.83 (Sy.x = 1.63; p